jenkins: don't post PR comment on errors when triggering Lite-CI (#241)

As the bot is does not have permission to trigger Jenkins Lite-CI builds
for some reason at the moment, and there's feedback about these error
comments not being useful to collaborators anyways, those comments are
muted for now.

Ideally github-bot maintainers should get notified about these errors,
as they're obviously not meant to be raised at all. But using
node core collaborators as proxy, manually telling bot maintainers about
errors surely isn't idealy either.

Refs #238
Refs #235 (comment)

Author: phillipj

scripts/trigger-jenkins-build.js

@@ -83,18 +83,13 @@ function triggerBuildIfValid (options) {
     }
 
     triggerBuild(options, function onBuildTriggered (err, result) {
-      let body = ''
-
       if (err) {
-        logger.error(err, 'Error while triggering Jenkins build')
-        body = 'Sadly, an error occurred when I tried to trigger a build. :('
-      } else {
-        const jobUrl = `https://ci.nodejs.org/job/${result.jobName}/${result.jobId}`
-        logger.info({ jobUrl }, 'Jenkins build started')
-        body = `Lite-CI: ${jobUrl}`
+        return logger.error(err, 'Error while triggering Jenkins build')
       }
 
-      createPrComment(options, body)
+      const jobUrl = `https://ci.nodejs.org/job/${result.jobName}/${result.jobId}`
+      logger.info({ jobUrl }, 'Jenkins build started')
+      createPrComment(options, `Lite-CI: ${jobUrl}`)
     })
   })
 }